C# Language Specification

Classes

A class is a data structure that may contain data members (constants and fields), function members (methods, properties, events, indexers, operators, instance constructors, destructors and static constructors), and nested types. Class types support inheritance, a mechanism whereby a derived class can extend and specialize a base class.

1. Class declarations

A class-declaration is a type-declaration (§9.6) that declares a new class.

class-declaration:
attributes_opt class-modifiers_opt partial_opt class identifier type-parameter-list_opt
class-base_opt type-parameter-constraints-clauses_opt class-body ;_opt

A class-declaration consists of an optional set of attributes (§17), followed by an optional set of class-modifiers (§10.1.1), followed by an optional partial modifier, followed by the keyword class and an identifier that names the class, followed by an optional type-parameter-list (§10.1.3), followed by an optional class-base specification (§10.1.4) , followed by an optional set of type-parameter-constraints-clauses (§10.1.5), followed by a class-body (§10.1.6), optionally followed by a semicolon.

A class declaration cannot supply type-parameter-constraints-clauses unless it also supplies a type-parameter-list.

A class declaration that supplies a type-parameter-list is a generic class declaration. Additionally, any class nested inside a generic class declaration or a generic struct declaration is itself a generic class declaration, since type parameters for the containing type must be supplied to create a constructed type.

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